Flechette assembly machine

ABSTRACT

Flechettes loaded into a pair of storage hoppers are supplied to vibrating feeders where they are oriented and fed to a row of inclined dispensing devices that drop them onto a grooved assembly plate where the flechette fins are radially oriented. A cam driven notched shuttle arrangement pushes rows, alternately axially displaced by one fin length, under a stationary holding device which holds the flechettes in proper alignment as subsequent rows are pushed across the assembly plate and under the holding device. Rows of flechettes will emerge from the holding device as additional rows of flechettes are added by the shuttle and they are sprayed with an adhesive and then heated to dry the adhesive, leaving the flechettes bonded together in sheets which may be easily handled for subsequent packaging.

[4 1 June 27, 1972 [54] FLECHETTE ASSEMBLY MACHINE [72] Inventors: Roy C. Buth; Arthur F. Schroeder, both of Evansville, Ind.

The United States of America as represented by the Secretary of the Navy [22] Filed: Sept. 3, 1970 [21] Appl. No.: 69,223

[73] Assignee:

[52] US. Cl. ..l56/563, 102/1, 102/924, l02/DIG. 7, 156/578, 206/3 [51] Int. Cl ..B32b 31/00, F421) 13/00, F42b 39/00 [58] Field of Search 156/558-559, 563, 156/578; lO2/DlG. 7, 92.4; 206/3 [56] References Cited UNITED STATES PATENTS 2,401,648 6/1946 Kahr ..156/559 X 2,821,221 1/1958 Jacquier et al.. ..l56/558 3,334,588 8/1967 Larsen ..l02/l R 2,816,755 12/1957 Dusenbury et a1. ..l56/558 X Primary Examiner-Philip Dier Attorney-Richard S. Sciascia and Thomas 0. Watson, Jr.

[57] ABSTRACT Flechettes loaded into a pair of storage hoppers are supplied to vibrating feeders where they are oriented and fed to a row of inclined dispensing devices that drop them onto a grooved assemblyplate where the flechette fins are radially oriented. A cam driven notched shuttle arrangement pushes rows, alternately axially displaced by one fin length, under a stationary holding device which holds the flechettes in proper alignment as subsequent rows are pushed across the assembly plate and under the holding device. Rows of flechettes will emerge from the holding device as additional rows of flechettes are added by the shuttle and they are sprayed with an adhesive and then heated to dry the adhesive, leaving the flechettes bonded together in sheets which may be easily handled for subsequent packaging.

9 Claims, 5 Drawing figures ARTHUR E SCHROEDER Jim 0. may).

ATTORNE Y PATENTEDJUNZ? I972 3, 573 47 SHEET 3 BF 3 FIG. 2 92 FLECHETTE ASSEMBLY MACHINE STATEMENT OF GOVERNMENT INTEREST BACKGROUND OF THE INVENTION The present invention relates generally to a flechette assembly machine and more particularly it pertains to a machine for assembling large numbers of flechettes into sheets suitable for subsequent packaging into a warhead.

Those concerned with the development of flechette weapons have long recognized the need for a high-speed automated machine that could solve the particular problems of flechette packing. One of the most serious problems that have faced the designers of flechette weapons is the orientation of the flechettes. It is, of course, to be desired that the flechette tips all be oriented forward so that when they are released from the pack for flight as individual missiles the flechettes will all be oriented in the proper direction for stable aerodynamic flight. The prior art, however, has not produced a machine for assembling the flechettes into sheets at a high rate of speed with all the flechette tips oriented in a forward direction.

Another serious difficulty encountered in the design of flechette weapons, wherein all flechette tips are pointed forward, is obtaining the tightest, densest pack of flechettes possible, in body to body contact, which is necessary for optimum efficiency and to avoid setback and spinup acceleration forces.

Since its inception, therefore, the art has sought a highspeed automated machine to assemble flechettes into sheets at a high mass production rate that provides the densest possible pack of flechettes oriented with all tips forward.

OBJECTS OF THE INVENTION Accordingly, it is an object of this invention to provide a fully automated machine for packing flechettes into sheets at high speeds with mass production output.

Another object is to provide an automatic, high-speed flechette assembly machine that will orient all flechette tips in a forward direction in a sheet of maximal density.

A further object of the invention is the provision of an automatic flechette assembly machine to position flechettes at a high rate of speed in rows of specified quantity to form sheets in an interlocked fin position, with body contact, in as dense a pattern as possible with the flechette tips all pointing in the same direction.

SUMMARY OF THE INVENTION These and other objects are attained by loading flechettes into a pair of storage hoppers and automatically feeding them, as required, to vibratory feeders having multiple tracks. The flechettes are oriented and fed to a row of inclined dispensing devices that drop the flechettes onto a grooved assembly plate which radially positions the fins of the flechettes. The flechettes are dropped directly in front of a notched shuttle, while the shuttle is in the back position. The shuttle makes two strokes per machine cycle and is actuated by a double cam arrangement. The first stroke of the shuttle pushes a row of flechettes in a diagonally forward direction and the remainder of the stroke is straight forward to place the first row of these flechettes under a stationary holding device in an interlocked position which holds them in proper alignment as subsequent rows are pushed across the assembly plate and under the holding device. The second stroke pushes a second row of flechettes in a diagonally forward direction one fin length farther sideways than the first stroke before continuing in a straight forward direction and placing the second row of flechettes under the holding device. Rows of flechettes will emerge from the holding device as additional rows of flechettes are added by the shuttle. As the oriented, adjacent rows of flechettes emerge in sheet form from the holding device they are sprayed with an adhesive and then heated to dry the adhesive, leaving the flechettes bonded together in sheets which may be easily handled for subsequent packaging.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the flechette assembly machine employing a preferred embodiment of the present invention;

FIG. 2 is a diagrammatic view of the notched shuttle arrangement of the present invention;

FIG. 3 shows a top view of the notched shuttle arrangement;

FIG. 4 shows a section of the device taken on line 4-4 of FIG. 3 looking in the direction of the arrows; and

FIG. 5 is a plan view of a sheet of flechettes assembled in an interdigitated array according to the flechette assembly machine of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Throughout this specification, the articles to be assembled into sheets will be referred to as flechettes, but it will be obvious that the machine throughout is adapted to the handling and packaging of any elongated and longitudinally geometrical, asymmetrical articles, and that some novel parts and func tions of the machine are adapted to and useful in the packaging of articles generally. The term flechette is, therefore, to be taken as illustrative, and not restrictive. As seen in FIG. 5, the flechettes have a body or shaft portion 10 which is pointed at the forward end 12, and four equally spaced fins 14 are formed around the rearward end thereof.

Referring in detail to FIG. 1 of the drawings, a flechette assembly machine is illustrated having a main frame 16 which supports a pair of storage hoppers l8 and 20 into which the flechettes are loaded. Also supported on the frame 16 are a pair of vibratory feeders 22 and 24 having multiple tracks 26 and 28, respectively. The feeders 22 and 24, in combination, have seven track ways but the number is not material and depends entirely on the number of articles desired in the rows of the final sheet. Forming a continuation of each of the multiple tracks 26 and 28 is a corresponding number of downwardly inclined dispensing devices 30 which drop the flechettes onto a grooved assembly plate 32.

The flechettes progress down the inclined dispensing devices or chutes 30 assisted by an air vibrator (not shown). A rotary escapement 31 is incorporated in the bottom of each dispensing device 30. Escapements 31 are oscillated by a cable 33 and drop the flechettes onto the grooved assembly plate 32. At the same time, the escapements 31 hold the remaining flechettes in the inclined chutes 30 preventing them from dropping down. A safety clutch (not shown), in the form of a pressure pointed set screw, partially engages a hole in the face of the escapement wheel 37. If a flechette gets jammed in the escapement the clutch will disengage and the defective flechette can be removed.

The grooved assembly plate 32 consists of two adjacent portions 34 and 36 as seen in FIG. 2. The first portion 34 of the plate 32 contains seven parallel grooves 38 that are in a diagonally forward direction with respect to the portion 34. At a point along plate 34, the seven grooves 38 divide into seven pairs of grooves 38 and 40. The second portion 36 of the plate 32 also contains seven pairs of grooves 42 that form a continuation of grooves 38 and 40. However, grooves 42 are in a substantially straight forward direction with respect to the portion 36 of plate 32. Each row of flechettes simultaneously delivered from the dispensing devices 30 is received in the grooves 38 into which the flechette fins l4 fit. Grooves 38, 40 and 42 are shallow and wide enough to contain only the fins 14 of the flechettes. The body portions 10 of the flechettes rest on the spaces 44 and 46 between their respective grooves 38, 40 and 42 as the flechettes are advanced along the assembly plate 32.

The main frame 16 carries a notched shuttle 48 in cooperative working relationship with the grooved assembly plate 32 wherein the number of slots or notches 50 corresponds in number to the seven grooves 38 in the first portion 34 of plate 32. The notches 50 are wide enough to clear the flechette fins 14 and fingers 52, between the notches 50, engage and push the body portions of the flechettes across the assembly plate 32.

The notched shuttle 48 makes two strokes per machine cycle and is actuated by a double cam arrangement or driving mechanism 54 to be described hereinafter. During the first stroke of each machine cycle the notches 50, with the flechette fins 14 therein, travel diagonally forward over the grooves 38 and continue straight forward over the first groove of each pair of grooves 42. During the second stroke of each machine cycle, the notches 50, with the flechette fins 14 therein, again travel diagonally forward over the grooves 38, but then switch to grooves 40 due to the cam arrangement 54 driving the notched shuttle 48. The notches 50 then continue straight forward over the second groove in each pair of grooves 42. The fingers 52 of the shuttle 48 move over the spaces 44 and 46 between the grooves 38, 40 and 42, respectively, during both the first and second strokes of each machine cycle.

The row of flechettes are advanced along the grooved assembly plate 32 by the notched shuttle 48 until they are placed under a holding device 56. The holding device 56 consists of a row of seven fixedly attached bars 58, each bar 58 being located above the spaces 46 a distance which allows the body portions 10 of the flechettes to be pushed under the bars 58 by the fingers 42 of the shuttle 48. The portions 60, between the bars 58 which holds them together, are located above grooves 42 a distance which allows the flechette fins 14 to be pushed under the portions 60 by the notches 50 of the notched shuttle 48.

The driving mechanism 54 for the notched shuttle 48, by which the rows of flechettes are transferred from the base of dispensing devices 30 to the holding device 56, and its operating means, will now be described with reference to FIGS. 2, 3, and 4:

The notched shuttle 48 is given its forward and backward motion by a link 62, which has one end attached to a mid point 64 of shuttle 48 and the other end attached to the upper arm 66 of a double transfer arm 68. The double transfer arm 68 is pivoted on a bearing 70 mounted on the base plate 72 of the machine. A carn follower 74 attached to a lower arm 76 of the double transfer arm 68 is actuated by a double lobe cam 78 which is formed on the bottom side of the cam mounting plate 80. The two lobes are identical so that the back and forth mo tion of the shuttle 48 is the same distance on each of the two strokes of a machine cycle.

The notched shuttle 48 slides back and forth in bearings 82 that are mounted on a side slide 84. Side slide 84 reciprocates sideways in bearings 86 that are also mounted on the base plate 72 of the machine. A cam follower 88 attached to the bottom side of slide 84 is actuated by a double lobe cam 90 formed on the top side of cam mounting plate 80. One lobe is one fin length farther sideways than the second lobe so that the second stroke of each machine cycle displaces the notched shuttle 48 one fin length farther sideways than the first stroke. ln this manner, the notches 50 of shuttle 48 align with the first groove of each pair of grooves 42 on the first stroke and align with the second groove of each pair of grooves 42 on the second stroke of a machine cycle.

A power source drives the shaft 92 which rotates the cam mounting plate 80 in a counter clockwise direction. As seen in FIG. 2, cam follower 88 will follow cam 90 causing slide 84 to slide to the left and carry shuttle 48 with it. Simultaneously, cam follower 74 will be following cam 78 and cause the double transfer arm 68 and link 62 to drive the shuttle 48 in a forward direction along the assembly plate 32. The resultant of these two simultaneous motions causes shuttle 48 to move in a substantially diagonally forward direction for a distance required to push the flechettes along grooves 38. The remainder of the stroke is straight forward, along grooves 42, to push the flechettes under the holding device 56 which holds the flechettes in proper alignment as subsequent rows are pushed across the assembly plate 32 and under the holding device 56.

Located adjacent to the grooved assembly plate 32 is an adhesive applicator 94, a heating unit 96 to cure the adhesive applied to the sheets and a parting device 98 to control the length of the sheets formed. A chute 100 proves a pick up station for the completed flechette sheets.

Referring now to FIG. 5, a sheet of interdigitated flechettes is shown assembled in array by the machine of the present invention. To achieve this array the flechettes are bulk loaded into the pair of storage hoppers l8 and 20 and are automatically fed as required to the vibratory feeders 22 and 24 having the multiple tracks 26 and 28. The flechettes are oriented and supplied to the row of inclined dispensing devices 30 that drop the flechettes onto the grooved assembly plate 32 where the flechette fins are radially oriented. While the shuttle 48 is in the back position, the flechettes are dropped directly in front of it at approximately a 15 angle, with the fins 14 being closer to the shuttle 48 than the flechette tips 12. The notches 50 in the shuttle 48 clear the fins l4 and locate the flechettes in an in-line position. The shuttle 48 makes two strokes per machine cycle and is actuated by the double cam arrangement 54 as described above. During the first stroke of the shuttle 48, the fingers 52 engage the flechette bodies 10 and the notches 50 engage the flechette fins 14 to push a first row 102 of flechettes in a diagonally forward direction over the spaces 44 and grooves 38, respectively. The remainder of the stroke is straight forward over the spaces 46 and along the first groove of each pair of grooves 42 to place the first row 102 of flechettes under the holding device 56 which maintains the flechettes in correct relation with each other and proper alignment as subsequent rows are pushed across the assembly plate 32 and under the holding device 56. The row 102 is axially aligned with all flechettes in the row pointed in the same direction, nose to tail. During the second stroke of the shuttle 48, a second row 104 of flechettes is pushed in a diagonally forward direction over the spaces 44 and grooves 38. The shuttle 48 is then actuated, by the second lobe of the double lobe cam 90, one fin length farther sideways than the first stroke and the flechette fins 14 are switched to grooves 40 before continuing in a straight forward direction over the spaces 46 and along the second groove of each pair of grooves 42 to place the second row 104 of flechettes under the holding device 56. The second row 104 of flechettes is then arranged adjacent to and in body to body contact with the flechettes in the first row 102, but shifted axially forward out of lateral alignment a distance equal to the length L of one flechette fin 14. This misalignment is for the purpose of preventing interference between the fins 14 of adjacent flechettes. The fins 14 of the flechettes in the first row 102 straddle the bodies or shafts 10 of the flechettes in the second row 104 and vice versa so that body to body contact is achieved and fin interference is avoided.

As the flechette assembly machine performs another cycle, a third row of flechettes 106 is added adjacent to and in body contact with the flechettes in the second row 104 but shifted rearwardly one flechette fin length to lie laterally opposite to the flechettes in the first row 102, but separated therefrom by the flechette bodies 10 in the second row 104. The fins in the second and third rows of flechettes are thus out of lateral alignment and straddle the shafts of the third and second flechette rows, respectively. Thus, it is seen that the fins 14 of the flechettes in each row straddle the shafts 10 of the flechettes in the rows on both sides of that row, and all the rows are in body to body contact with the adjacent rows on both sides.

Rows are added in this alternating staggered fashion until a sheet of a desired dimension is formed. Rows of flechettes will emerge from the holding device 56 as additional rows of flechettes are added by the shuttle 48. As the oriented rows of flechettes emerge in sheet form an adhesive is automatically applied by the adhesive applicator 94. The heating unit 96 evaporates the solvent from the adhesive, leaving the rows of flechettes bonded together in a semi-rigid sheet. Instantaneous curing of the adhesive is accomplished by means of a silicon immersion heater of approximately 20 watts which is embedded in the grooved assembly plate 32. The parting device 98 having a multiple location feature will part the sheets of flechettes in various required lengths. The sheets of bonded flechettes will then slide down chute 100 and be transported to an assembly area.

Flechette sheet stacking may be automated by means of a magnetic lifting device which lifts and positions a flechette sheet on an adjacent conveyor and deposits it on top of an existing flechette sheet, if sufficient volume production merits this device. Lifting and depositing will be controlled on the center line of the flechette sheet to insure that the symmetry of the flechette stack is maintained.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings.

What is claimed is:

l. A machine for assembling flechettes into sheets at high speed having all flechette tips oriented in the same direction comprising:

means for feeding flechettes to a transfer station in aligned rows with all flechettes in the rows pointed in the same direction;

means for transferring said rows of flechettes from said transfer station to a holding device whereby said rows are placed in body to body contact alternately axially displaced by one fin length;

means for applying adhesive to bond said flechette rows into sheets; and

means for parting said sheets of flechettes into specified lengths.

2. A flechette assembly machine according to claim 1 wherein said transfer means comprises a grooved plate to maintain said flechette rows in alignment during transfer from said transfer station to said holding device.

3. A flechette assembly machine according to claim 2 wherein:

said feeding means include a row of dispensing devices which place a row of flechettes on said grooved plate and means to supply flechettes to said dispensing devices in an oriented manner; and

said transfer means further including a cam driven shuttle to transfer the flechette rows over said grooved plate and under said holding device.

4. A flechette assembly machine according to claim 3 wherein:

said cam driven shuttle includes a plurality of fingers and notches to transfer said rows of flechettes; and

said grooved plate having a plurality of grooves along which said notched shuttle advances the flechettes to a point under said holding device which holds the rows of flechettes in proper alignment as subsequent rows are pushed across the assembly plate and under the holding device.

5. A flechette assembly machine in accordance with claim 4 wherein said cam driven shuttle further includes a cam controlled slide over which said notched shuttle moves and a cam controlled linkage to actuate said notched shuttle.

6. A machine for assembling articles in an interdigitated array to form a sheet comprising:

means for feeding articles to a transfer station in aligned rows including a row of dispensing devices and means to supply articles to said dispensing devices;

a grooved plate to maintain said rows in alignment during transfer;

a holding device coo rating with said transfer means to eliver said rows of articles from said transfer station to the holding device and the grooved plate;

said transfer means comprising escapement means to deliver said articles from said rows at said transfer station one at a time to said grooved plate and a cam driven shuttle to transfer said rows along said grooved plate to said holding device where adjacent rows of articles form a sheet.

7. An assembly machine in accordance with claim 6 further comprising adhesive applying means to bond said rows of articles into semi-rigid sheets.

8. An assembly machine in accordance with claim 7 further comprising parting means to separate said sheets into specified lengths.

9. A flechette assembly machine according to claim 1 wherein said transfer means comprises plate means to hold said flechette rows in alignment during transfer from said transfer station to said holding device;

shuttle means to move said flechette rows over said plate means and under said holding device; and

escapement means to deliver flechettes from said rows at said transfer station one at a time to said plate means. 

1. A machine for assembling flechettes into sheets at high speed having all flechette tips oriented in the same direction comprising: means for feeding flechettes to a transfer station in aligned rows with all flechettes in the rows pointed in the same direction; means for transferring said rows of flechettes from said transfer station to a holding device whereby said rows are placed in body to body contact alternately axially displaced by one fin length; means for applying adhesive to bond said flechette rows into sheets; and means for parting said sheets of flechettes into specified lengths.
 2. A flechette assembly machine according to claim 1 wherein said transfer means comprises a grooved plate to maintain said flechette rows in alignment during transfer from said transfer station to said holding device.
 3. A flechette assembly machine according to claim 2 whErein: said feeding means include a row of dispensing devices which place a row of flechettes on said grooved plate and means to supply flechettes to said dispensing devices in an oriented manner; and said transfer means further including a cam driven shuttle to transfer the flechette rows over said grooved plate and under said holding device.
 4. A flechette assembly machine according to claim 3 wherein: said cam driven shuttle includes a plurality of fingers and notches to transfer said rows of flechettes; and said grooved plate having a plurality of grooves along which said notched shuttle advances the flechettes to a point under said holding device which holds the rows of flechettes in proper alignment as subsequent rows are pushed across the assembly plate and under the holding device.
 5. A flechette assembly machine in accordance with claim 4 wherein said cam driven shuttle further includes a cam controlled slide over which said notched shuttle moves and a cam controlled linkage to actuate said notched shuttle.
 6. A machine for assembling articles in an interdigitated array to form a sheet comprising: means for feeding articles to a transfer station in aligned rows including a row of dispensing devices and means to supply articles to said dispensing devices; a grooved plate to maintain said rows in alignment during transfer; a holding device cooperating with said transfer means to deliver said rows of articles from said transfer station to the holding device and the grooved plate; said transfer means comprising escapement means to deliver said articles from said rows at said transfer station one at a time to said grooved plate and a cam driven shuttle to transfer said rows along said grooved plate to said holding device where adjacent rows of articles form a sheet.
 7. An assembly machine in accordance with claim 6 further comprising adhesive applying means to bond said rows of articles into semi-rigid sheets.
 8. An assembly machine in accordance with claim 7 further comprising parting means to separate said sheets into specified lengths.
 9. A flechette assembly machine according to claim 1 wherein said transfer means comprises plate means to hold said flechette rows in alignment during transfer from said transfer station to said holding device; shuttle means to move said flechette rows over said plate means and under said holding device; and escapement means to deliver flechettes from said rows at said transfer station one at a time to said plate means. 